Technical Tip: SSL VPN web mode showing '403 Forbidden' error

HiralShah · ‎02-02-2024

Description

This article describes the case when it is desired to access the VPN using web mode but it is showing 403 Forbidden error while SSL VPN is configured with SAML authentication.

Scope

FortiGate.

Solution

SSL VPN web mode gets the error as below when configured with SAML authentication.

Make sure web-mode is enabled in the SSL VPN portal:

config vpn ssl web portal

edit "full-access"

set web-mode enable

Warning: Please note that the legacy SSL VPN web mode feature is disabled by the global sslvpn-web-mode setting.

As the warning displayed, web mode is disabled globally so can not enable it in the full-access portal directly.

Enable the web-mode globally first:

config sys global

set sslvpn-web-mode enable

end

Now the web mode of SSL VPN should work as expected after enabling web-mode for specific portals. To enable the web mode for specific portals run the command as shown in step 1.

If the issue persists, contact the TAC team.